After September 11, 2001, TV bulletins about attempts to destroy al-Qaeda and the Taliban featured footage of Quetta, a city in Pakistan on the fabled North West Frontier, just south of Afghanistan's Kandahar (see Map in Simpson). The news recalled memories of the weeks I'd spent there, 42 years previously. More came flooding back as I leafed through the pages of my photo album.

Almost naked, I sweated on a Karachi hotel bed, the ceiling fan spinning above me. What had I let myself in for? Disconsolate, missing my wife and new firstborn son who were already back home in Australia, I could well understand why Somerset Maugham's expatriate Englishmen took to drink in the equatorial Empire.

It was the northern spring of 1959, and I was overnighting in Karachi, then Pakistan's capital, en route to Quetta, near the border with Afghanistan. After three and a half years away from Australasia gaining specialist ophthalmic training in England and the USA, I'd allowed an American colleague to entice me to detour on my way home — for a 10-week stint at Quetta's Church Missionary Society Hospital. I hadn't thought of arranging professional indemnity insurance (!), and I'm not even sure travel insurance would have covered all the potential risks.

The next morning, I boarded my train to the north. In addition to my ticket, I'd purchased, on advice, my personal air conditioner — a 30kg block of ice in a tin tub placed under my seat for the 24-hour trip. As we journeyed through the Desert of Sind, on the strategic railway built by the British in 1895, stories of the British Raj, India's frontier, the Khyber Pass, the Bengal Lancers and Gunga Din ran through my head. The last remnants of my ice block were melting away as the train chugged up the final slope of the Bolan Pass to enter the Quetta plateau.

The city of Quetta is a hill-station, about 1700 metres above sea level, in a valley ringed by snowy mountains rising to about 2500 metres. In spring, the valley floor is lush and productive, but the overgrazed hillsides are always bare.

The city was rebuilt after being destroyed by earthquake in 1935. Low-rise to the eye, Quetta was, to me, reminiscent of an Australian country town. The population was about 30 000 in winter, doubling in summer.

Quetta has long-standing military connections, beginning with its name — derived from "kuwetta", meaning "fort". In the centre of town, on a hillock, is the famed Red Fort antedating British rule. The British arrived in about 1876, encountering tribal groups of Brahuis and Baluchis, as well as the Pathans, the Pashtun nomads. Fearing Russian encroachment via Afghanistan, the British military commanders of the day considered the chain of missionary hospitals positioned along the frontier, including the one at Quetta, to be the equivalent of several battalions. These missions, in effect, garrisoned the border with Afghanistan, supplementing the forts along the thousand miles from Iran to China. During the Second World War, although not an active theatre of war, this garrison town was the second-largest military establishment in the British Empire, after Aldershot. Quetta's military cemetery holds the graves of soldiers from all over the old Empire, from many cultures and religions.

In 1959, Quetta still retained the Commonwealth Staff College founded at the height of Empire in 1907. Security was still a concern and became evident to me in a personal way. One day, when I'd cycled out of town to photograph the scenic city and surrounds, two policemen pounced on me and confiscated my camera film — India and Pakistan were already battling over Kashmir and there had been recent bomber activity at the Indo-Pakistan border.

Quetta's mission hospital was originally established in 1886, and had been rebuilt after the earthquake. In the courtyard there were small cottages forming the caravanserai where patients were nursed by relatives who also took care of food and cooking.

Throughout the day, electric amplifiers and loudspeakers alerted us to the call of the muezzin, reminding our Christian medical island of the dominant culture that lapped against the walls of the hospital compound. Purdah (seclusion) and veiling were still upheld in Quetta despite its cosmopolitan community. The hospital had a segregated women's section, the zenana wards.

The hospital served the city and the region, catering particularly to the trans-border nomadic Pathans who moved down through the Bolan Pass to the southern plains during the winter, returning to the hills of Afghanistan during the summer. Accordingly, these tribal nomads had two opportunities each year to benefit from Western medicine.

Cataracts and neglected chronic diseases were common presentations, as was diarrhoea. I myself suffered diarrhoea on several occasions and progressively lost weight during my stay. Faecal tests positive for blood and/or amoebae sentenced one to amoebicides; negatives dictated sulfas, to which my bugs responded.

The diarrhoea was surely related to the town's contaminated water supply. Irrigation water from the city's reservoirs flowed through the streets alongside the footpaths. Using removable paddles, the waterman selectively diverted the flow into separate open channels for individual sections of the town on given days. Not surprisingly, the water reaching our vegetable gardens in the hospital compound was murky. This public health issue didn't seem to agitate either the city authorities or, in general, the Western doctors!

In winter, the hospital ran an outreach clinic at Shikarpur, 200 miles to the south. Many such clinics, known as "cataract camps", were held on the Indian subcontinent under missionary auspices, foreshadowing the Fred Hollows Foundation.

Every operation began with a Christian prayer. For the anxious patient, this was extra premedication. Local anaesthesia was used for cataract operations — patients' eyelids were kept open during the procedure with a pair of locally made fork retractors, handheld by the assistant, one of the male nurses trained in the hospital's own program. Graefe section with conjunctival flap was standard, progressing to intracapsular extraction. I carried out over 100 cataract procedures in my 10 weeks, and many plastic operations on eyelids and tear ducts. I treated one patient with retinal detachment. I also assisted at numerous general surgical procedures and outpatient clinics.

The hospital's surgeons — Pakistani Christians as well as English — were skilled in all aspects of surgery (ophthalmology included). I saw many cases of advanced cancers of the head and neck such as I'd never before witnessed that were managed with massive excisions and repairs.

Radiotherapy was available in the form of radium needles. When two of those valued needles were mislaid, many of the hospital staff devoted the day to search for them — they turned up when an American geologist scanned the rubbish tip with his Geiger counter!

The social atmosphere throughout my stay was memorable. I was made to feel one of the family by the hospital's director, Dr Ronnie Holland, son of a previous director, Sir Henry Holland, who had been knighted for heroism in the 1935 earthquake. His wife, Joan, was a remarkable woman who, while pregnant, had survived near-fatal polio, being kept alive with manual resuscitation until an iron lung could be procured and repaired. She now worked from her wheelchair, as nurse-anaesthetist.

Sunday was a real day of rest, commencing with chapel and then a relaxing picnic lunch on the English lawn of the hospital gardens, next to a rich and varied orchard. It was here that I became partial to green tea.

At the Hollands' table, I met intriguing characters from many cultures. They included the indigenous Bishop of Karachi, Chandhu Ray — an amiable man with whom to exchange philosophies; Parsee merchants, who were the first to tell me that their dead were disposed of on special towers, for the vultures; and American scientists working for United Nations agricultural or prospecting agencies. Among other social engagements were invitations to dinner with Australian army officers at the Staff College.

When it came time for the Hollands to open the hospital's summer cottage in the hill-station of Ziarat, 70 miles east, and elevated some 900 metres above Quetta, I accompanied them. We set off for the weekend through a narrow defile to a higher plateau before climbing the dusty hills on one side of the broad valley. As I swallowed the dust and, terrified, looked over the rim of the snaky alpine tracks, I was told that Alexander the Great had passed along the valley below after conquering Swat, in the border regions near China. At various points in our passage, we came across clusters of flags on poles like those marking golf holes, but twice as tall — markers of nomad graves. At 630 metres above sea level, juniper trees suddenly appeared on the valley walls, creating a new demarcation line between the bare slopes below and the trees, which only thrived above this height. The mountain air was laden with the scent of thyme, as well as juniper.

At the end of my adventure, returning to my hotel in Karachi, I was surprised to find that Bishop Ray had left a message for me. He invited me to lunch with him, and then came to the airport to see me off. His touching courtesy prompted me to ponder the situation of the Christian minority and its missionary doctors, whose lives I had shared.

My missionary friends were not confounded by their inability to care for everyone, everywhere in the region. They were realists, content to do all they could to meet local needs. To them, their calling didn't involve self-sacrifice (although a young English nurse did die suddenly during my visit). Perhaps the missionary urge, previously a preserve of the Christian medical missionaries, can be best illustrated by paraphrasing Sir Henry Holland:

Today, the North West Frontier is an even more dangerous place than it was in 1959. Opposition to the presence, and even to the work, of medical missionaries has intensified.

I reflected on what the hospital and I had provided for each other. I'd assisted slightly with the patient load. Quetta gave me the benefits of concentrated experience with advanced, neglected, untreated disease; further medical and surgical insight; and the privilege of working with admirable colleagues dedicated to the impressive people native to this frontier. I'd learnt much more in Quetta than surgery alone.